Paramedics and police were stationed at the New Haven Green all day as more and more people showed signs of overdosing, according to WABC-TV in NY, which added that some users fell unconscious while others vomited.

No deaths were reported, but officials said two people suffered life-threatening symptoms.

CT police have made multiple arrests in connection with 76 overdose cases at a New Haven park.

While K2 may look like marijuana, drug experts say it is far more potent and unsafe. No deaths were reported, and most people brought to hospitals have been discharged, officials said.

Synthetic opiates like fentanyl, which is 30-50 times more potent than heroin, are extremely unsafe, with high risks of overdose and death.

"Throughout the day [Wednesday] it was extremely busy, we had six or seven people at the same time, kind of put a little bit of stress, not only on emergency services personnel, EMS personnel, but throughout the entire city", said Rick Fontana, New Haven Office of Emergency Operations.

Officials said the blood of Wednesday's victims was being tested to see what exactly they ingested.

The mass overdose began Tuesday night and forced police to continue monitoring the Green late into Wednesday night.

"Bodies are literally dropping all around me from suspected drug overdoses", said Mario Boone, a journalist who was at the park, via Twitter. "There's even three churches inside the park", David Hartman, a New Haven Police spokesman told CNN.

As of 10 a.m. Friday, there haven't been any new reports of more overdoses.

Connecticut Gov. Dannel Malloy tweeted that the emergency in New Haven was "deeply troubling and illustrative of the very real and serious threat that illicit street drugs pose to health of individuals".

Hawk said the people who tested positive may have taken other drugs laced with fentanyl in addition to the synthetic marijuana, which is plant material sprayed with drugs and chemicals.

Authorities said most of the New Haven patients responded to high doses of Narcan given at the hospital and they were released.

New Haven Green is a large park and recreation area in the city's downtown. He said the Green has become "a place of despair" and "no longer an attraction for families or economic development".